Quantum Dissipation in a Neutrino System Propagating in Vacuum and in Matter

Considering the neutrino state like an open quantum system, we analyze its propagation in vacuum or in matter. After defining what can be called decoherence and relaxation effects, we show that in general the probabilities in vacuum and in constant matter can be written in a similar way, which is not an obvious result in this approach. From this result, we analyze the situation where neutrinos evolution satisfies the adiabatic limit and use this formalim to study solar neutrinos. We show that the decoherence effect may not be bounded by the solar neutrino data and review some results in the literature. We discuss the current results where solar neutrinos were used to put bounds on decoherence effects through a model-dependent approach. We conclude explaining how and why this models are not general and we reinterpret these constraints.Comment: new version: title was changend and was added a table. To appear at Nucl. Physic.

On the taxonomic identity and nomenclature of Cyperus megapotamicus (Cyperaceae)

Cyperus megapotamicus (A. Spreng.) Kunth is a nomenclatural synonym of Rhynchospora megapotamica (A. Spreng.) H. Pfeiff. but was originally misapplied to a species of Cyperus. Contrary to the rules, both species names are in current use in different genera. We here clarify the perpetuated taxonomic and nomenclatural confusion regarding the identity of C. megapotamicus sensu Kunth and related names and conclude that Cyperus jaeggii Boeckeler is the correct name to be adopted. We provide an amended circumscription of this species, with Cyperus mauryi Kuntze and Pycreus nematodes Schrad. ex C. B. Clarke as its newly proposed heterotypic synonyms. Additionally, lectotypes are designated for the names Scirpus megapotamicus A. Spreng., Rhynchospora maculata Maury, Rhynchospora luzuliformis var. elongata Kuntze, Rhynchospora luzuliformis var. subcapitata Kuntze, Cyperus jaeggii, Cyperus mauryi and Pycreus nematodes.Peer reviewe

Characterisation of the sintering behaviour of Waelz slag from electric arc furnace (EAF) dust recycling for use in the clay ceramics industry

Waelz slag is an industrial by-product from the recovery of electric arc furnace (EAF) dust which is mainly sent to landfills. Despite the different chemical and mineralogical compositions of Waelz slag compared to traditional clays, previous experiments have demonstrated its potential use as a clay substitute in ceramic processes. Indeed, clayey products containing Waelz slag could improve mechanical and environmental performance, fixing most of the metallic species and moreover decreasing the release of some potential pollutants during firing. However, a deeper understanding of the complex phase transformations during its thermal treatment and the connection of this behaviour with the end properties is desirable in order to explain the role that is played by the Waelz slag and its potential contribution to the ceramic process. For this purpose, in the present study, the chemical, mineralogical, thermal and environmental behaviour of both (i) unfired powdered samples, and (ii) pressed specimen of Waelz slag fired up to different temperatures within the typical range of clay based ceramic production, has been studied. The effect of the heating temperature on the end properties of the fired samples has been assessed. In general, an increase of the firing temperature promotes sintering and densification of the products and decreases the open porosity and water absorption which also contributes to the fixation of heavy metals. On the contrary, an increase in the leaching of Pb, Cr and Mo from the fired specimens is observed. This can be attributed to the creation of Fe and Ca molybdates and chromates that are weakly retained in the alkali matrix. On the other side, at temperature above 950 °C a weight gain related to the emission of evolved gases is observed. In conclusion, the firing temperature of the ceramic process is a key parameter that affects not only the technical properties but also strongly affects the leaching behaviour and the process emissions.The authors gratefully acknowledge the financial support for this research by the BEFESA STEEL R&D, S.L.U. Company, Erandio, Biscay (España) and the framework of the Spanish Ministry of Science and Innovation Project (CTM 2009-11303 TECNO).Peer reviewe

Cell-based therapies for stroke : promising solution or dead end?

The introduction of recanalization procedures has revolutionized acute stroke management, although the narrow time window, strict eligibility criteria and logistical limitations still exclude the majority of patients from treatment. In addition, residual deficits are present in many patients who undergo therapy, preventing their return to premorbid status. Hence, there is a strong need for novel, and ideally complementary, approaches to stroke management. In preclinical experiments, cell-based treatments have demonstrated beneficial effects in the subacute and chronic stages following stroke [1; 2; 3] and therefore are considered a promising option to supplement current clinical practice. At the same time, great progress has been made in developing clinically feasible delivery and monitoring protocols [4]. However, efficacy results initially reported in clinical studies fell short of expectations [5] raising concerns that cell treatment might eventually share the ‘dead end fate’ of many previous experimental stroke therapies. This Research Topic reviews some of the latest and most innovative studies to summarize the state of the art in translational cell treatments for stroke

Patterson Function from Low-Energy Electron Diffraction Measured Intensities and Structural Discrimination

Surface Patterson Functions have been derived by direct inversion of experimental Low-Energy Electron Diffraction I-V spectra measured at multiple incident angles. The direct inversion is computationally simple and can be used to discriminate between different structural models. 1x1 YSi_2 epitaxial layers grown on Si(111) have been used to illustrate the analysis. We introduce a suitable R-factor for the Patterson Function to make the structural discrimination as objective as possible. From six competing models needed to complete the geometrical search, four could easily be discarded, achieving a very significant and useful reduction in the parameter space to be explored by standard dynamical LEED methods. The amount and quality of data needed for this analysis is discussed.Comment: 5 pages, 4 figure

Intoxicación por litio desencadenada por un proceso febril. A propósito de un caso

IntroducciónEl litio es un fármaco muy utilizado en el trastorno bipolar tipo I. El principal problema de su utilización deriva del estrecho margen terapéutico, que aconseja la monitorización de sus concentraciones plasmáticas, así como prestar atención a las interacciones con otros fármacos, a las medidas dietéticas (dietas hiposódicas y otras pérdidas de sodio asociadas con diarreas o pérdidas de electrólitos) y a la hipovolemia, con el fin de evitar su toxicidad en sobredosificación1. Su mecanismo de acción se desconoce, aunque es probable que ejerza su acción desde dentro de la propia célula por desplazamiento del sodio, potasio, magnesio o calcio. Se sabe que inhibe la liberación de la dopamina y noradrenalina (de ahí su acción antimaníaca) y aumenta la acción de la serotonina.Caso clínicoPaciente varón de 69 años de edad con antecedentes de hipertensión arterial, trastorno bipolar desde hacía 12 años con predominio de síntomas depresivos, extrapiramidalismo medicamentoso (con alteraciones en la marcha, temblor de reposo, inestabilidad y caídas frecuentes, sin claro deterioro cognitivo) desde hacía 4 años. Actualmente seguía tratamiento con parmipexol 0,7 mg (1 comprimido/8 h), levodopa- carbidopa 25/100 mg (1 comprimido/ 8 h), carbonato de litio 400 mg (2 comprimidos/24 h), atenolol 100 mg (1 comprimido/24 h), enalaprilo 20 mg más hidroclorotiacida 12,5 mg (1 comprimido/ 24 h) y clorhidrato de maprotilina 75 (1,5 comprimido/24 h). Se le visitó en su domicilio por presentar malestar general, fiebre y hematuria macroscópica. Se le practicó multistix, que fue compatible con infección urinaria, y se inició tratamiento con amoxicilina-ácido clavulánico (500 mg/8 h). A las 48 h se le revaluó y se detectó en la exploración aumento de la rigidez y dificultad para moverse, junto con rueda dentada. Se decidió mantener el tratamiento y volver a evaluar al paciente al término de la medicación. Tras 10 días de tratamiento antibiótico mejoró su estado general y disminuyó la rigidez, pero persistía la febrícula vespertina. A los 5 días de finalizar el tratamiento antibiótico el paciente fue remitido al hospital por reaparición de fiebre elevada (sin evidencia de foco infeccioso en la exploración) junto con bradipsiquia, torpeza en la marcha, desorientación y temblores.En la exploración neurológica inicial en el hospital destacaron una puntuación de Glasgow de 10, estupor, bradipsiquia, trastorno del lenguaje (en comprensión y nominación), sin signos de afección piramidal. Los pares craneales no pudieron valorarse por falta de colaboración del paciente, que presentaba mioclonías de acción generalizadas sin fasciculaciones, así como reflejo palpebral hiperexaltado, reflejo osteotendinoso de 5/5 y reflejo cutaneoplantar en flexión. El resto de la exploración física por aparatos fue normal. En la analítica destacaban: creatinina de 1,5 mg/dl, creatincinasa de 278 U/l, lactatodeshidrogenasa de 543 U/l, proteína C reactiva de 37 mg/l y litemia de 2,15 mmol/l (rango terapéutico, 0,7-1,4); el resto de la bioquímica, hemograma, coagulación y hormonas tiroideas eran normales. En cuanto a la microbiología, el urocultivo, los hemocultivos y el estudio del líquido cefalorraquídeo fueron normales. Por lo que se refiere a las pruebas de imagen, tanto la radiografía de tórax como la tomografía computarizada craneal resultaron normales. En el electrocardiograma destacó un alargamiento del QT.Durante su ingreso presentó hipotensión arterial que requirió la administración de expansores del plasma y dopamina en perfusión. Tras proceder a la retirada del litio, dada la intoxicación moderada que presentaba el paciente, se apreció una mejoría del estado general y neurológico del paciente, que se resolvieron por completo cuando se le dio de alta.Discusión y conclusionesLas interacciones más peligrosas del litio se producen con los diuréticos tiacídicos (que aumentan las concentraciones plasmáticas del litio, por lo que se recomienda reducir la dosis de éste en un 30-50%) y con los antiinflamatorios no esteroideos (que tienden a reducir la depuración renal del litio aumentando así la concentración sérica; como alternativa se aconseja administrar paracetamol o ácido acetilsalicílico)2. Los diuréticos de asa y ahorradores de potasio también pueden interaccionar, aunque con menor relevancia. Se ha descrito neurotoxicidad con el uso combinado de litio y fluoxetina, neurolépticos, antihipertensivos (enalapril), carbamacepina y metildopa. Existen comunicaciones de interacción con antagonistas del calcio (verapamilo, diltiazem), antimicrobianos (metronidazol, espectinomicina), xantinas (teofilinas), quimioterápicos (cisplatino) y estimulantes centrales (mazindol)3.En este caso, el paciente se mantuvo estable a pesar de los múltiples fármacos que utilizaba y sus posibles interacciones, hasta presentar el proceso febril que desencadenó una intoxicación moderada por litio. Atendiendo a los valores de litemia, las intoxicaciones se clasifican en leves (1,5-2 mEq/l), moderadas (2-2,5 mEq/l) y graves (> 2,5 mEq/l). De los síntomas y signos de intoxicación moderada el paciente presentó los siguientes: estupor, mioclonías, reflejos osteotendinosos exaltados, hipotensión arterial y trastornos en la conducción electrocardiográfica4.Es imprecindible prestar gran atención a todos los procesos agudos que pueden alterar el equilibrio que mantienen los pacientes polimedicados y con fármacos con muy estrecho margen terapéutico.Nuestro agradecimiento a Avelina Magallón Fernández, Félix Fernández Suárez y Carlos J. Vallés Paulés

Tolerance of cucumber crop to salinity in greenhouse

Neste trabalho se objetivou avaliar a cultura do pepino conduzido sobre condição salina, proveniente de sais fertilizantes, com seis níveis de salinidade do solo (1,5; 2,5; 3,5; 4,5; 5,5 e 6,5 dS m-1). O experimento foi conduzido na área experimental do Departamento de Engenharia Rural da ESALQ/USP, Piracicaba, SP. O plantio foi realizado em vasos utilizando-se solo arenoso. A época de plantio foi de 28/08/07 a 20/10/07. Como principais resultados, verificou-se que a produtividade máxima obtida foi 2,45 kg m-2 para o nível de salinidade 3,5 dS m-1; com os valores de produção relativa obteve-se a salinidade limiar (SL) de 4,08 dS m-1, com uma queda de produção, após o ponto limiar na ordem de 19,33% por dS m-1, para cada aumento de uma unidade de salinidade do solo.The objective of this work was to evaluate the cucumber crop in saline conditions resulting from fertilizer salt, under six levels of soil salinity (1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 dS m-1). The study was carried out in the experimental area of the Department of Rural Engineering of the ESALQ/USP, Piracicaba/SP, Brazil. The planting was carried out in recipients using sandy soil during the period of 28/08/07 to 20/10/07. As the main results, it was verified that the maximum productivity was 2.45 kg m-2 for the salinity level of 3.5 dS m-1, that with the values of relative production the threshold salinity (SL) observed was of 4.08 dS m-1, and that there was a decline of 19.33% in production for unit increase of soil salinity above the threshold point

Using Typical Consumption Profiles to Stablish the Consumption Level for Short Time Periods

The current practices in the consumption metering by electricity utilities is currently largely based on monthly consumption reading. The consumption metering device is always calculating the cumulative consumption. Then, it is possible to calculate the difference between the actual and the previous consumption evaluation in order to estimate the monthly consumption. The power systems planning needs in many aspects to handle consumption data obtained for shorter periods, namely in the Demand Response programs planning. The work presented in this paper is based on the application of typical consumption profiles that are previously defined for a certain power system area. Such profiles are then used in order to estimate the 15 minutes consumption for a certain consumer or consumer type